With the development of the manufacturing industry, the manufactured workpieces are becoming increasingly complicated and flexible. The demand for high-precision and complex-shaped forgings is increasing in device parts, that is, the demand for complex forming devices capable of completing various forming requirements is also increasing. The complex forming device has a poor working environment, a complicated structure, various functions, and various working conditions, and involves a relatively large amount of operation data. Therefore, it is difficult to estimate the performance operating status of the complex forming device, and then it is also difficult to determine a maintenance policy of the complex forming device according to the performance operating status. Therefore, how to select a suitable maintenance policy of the complex forming device to reduce maintenance costs is a technical problem urgently to be solved in the device maintenance field.